This invention relates generally to medical equipment intended to increase oxygenation of the blood of a patient who has insufficient pressure in the lungs following exhalation.
Acute respiratory distress syndrome (“ARDS”) is a lung condition that prevents enough oxygen from getting to the lungs and into the blood. This condition can be life-threatening if not treated appropriately and expeditiously. ARDS leads to a buildup of fluid in the air sacs (alveoli) of a lung which prevents enough oxygen from passing into the bloodstream. The fluid buildup also makes the lungs heavy and stiff, which decreases the lungs' ability to expand. The level of oxygen in the blood can stay dangerously low, even if the person receives oxygen from a breathing machine (ventilator) through a breathing tube (endotracheal tube). Blood and fresh inspired gas must be in close proximity to one another for gas change to occur
A method to help prevent lung collapse (i.e. collapse of individual alveoli) at the end of expiration in critically ill mechanically ventilated patients is known as positive end-expiratory pressure (known as “PEEP”). Described briefly, PEEP refers to keeping a small amount of pressure in the lung at the end of expiration rather than letting the lung return to atmospheric pressure. The pressure remaining in the lung acts as a force pushing outward on the alveoli and holding them open to receive oxygen. In short, more oxygen is added to the blood, i.e. increased oxygenation of the blood. Traditionally, PEEP is a method provided mechanically by a ventilator in an intubated patient on a ventilator machine.
In a typical ventilation setup, a patient receives fresh oxygen or enhanced oxygenated air through tubes placed into his nostrils and into his lungs (“inhalation) while air is exhaled from his lungs into a ventilation machine through a tracheal tube. A one-way as positive end-expiratory pressure (PEEP) valve may be situated in the exhalation stream that provides mechanical resistance intended to increase the patient's lung pressure and, thereby, increasing the oxygenation of the patient's blood.
Although presumably effective for its intended use, the current method of treating a dangerously distressed patient with a full ventilator and intubated patient is undesirable for a patient that is not intubated and not being treated on a full ventilator setup. Stated another way, it would be desirable for a patient capable of inhaling and exhaling on his own to have a bi-directional oxygenation apparatus that allows the patient to inhale air through his mouth and then to exhale through his mouth with mechanical resistance being given to the exhalation, whereby to increase the pressure in the lung at the end of exhalation and, as a result, increase the oxygenation of his blood. In addition, it would be desirable to a bi-directional oxygenation apparatus having a mouthpiece and that is handheld.